Effect modification of dietary diversity on the association of air pollution with incidence, complications, and mortality of type 2 diabetes: Results from a large prospective cohort study

Background: It remains unknown whether the dietary diversity score (DDS) could modify the association of longterm exposure to individual air pollutants and the mixture of various pollutants with the incidence, complications, and mortality of type 2 diabetes (T2D). Methods: We included 162,579 participants from the UK Biobank who had >= one 24-h dietary assessment and were free of diabetes or diabetes complications before their last response date of the 24-h dietary assessment. Exposure to benzene, NOx, NO2, SO2, PM10, and PM2.5 was estimated at each participant's residential location using a bilinear interpolation algorithm based on air dispersion models on a 1 km x 1 km grid. The DDS was calculated based on repeated 24-h dietary assessments. The outcomes were the incidence, complications, and mortality of T2D. Associations of individual pollutants and multiple pollutants mixtures with outcomes were assessed using Cox proportional hazards regression models and the quantile g-computation approach, respectively. We further stratified these analyses by DDS.